Characterization of Polysaccharopeptides from Pleurotus ostreatus mycelium: assessment of toxicity and immunomodulation in vivo

Characterization of hot water polysaccharopeptides from the culture medium of Pleurotus ostreatus mycelium, as well as the assessment of its toxicity and immunomodulatory effects on mice, were carried out. Physicochemical studies revealed that the structure of crude polysaccharopeptides consisted mainly of B-D-glucans with (1-3) (1-6) glucosidic linkages, and they had a high molecular weight of 316.26 kDa. Acute toxicity studies showed that polysaccharopeptides were not lethal after 24 h, in mice given i.p. 854 mg/kg or less. Intraperitoneal administration of mice with polysaccharopeptides, at doubling doses (25, 50 and 100 mg/kg), thrice weekly for five consecutive weeks, has shown that although the lowest dose induced the maximum endogenous alpha-interferon production (213.2%), yet it reduced significantly the body weight gain of animals (39.56%) and exhibited a low mortality effect (12.50%) at the end of the experiment.